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/// \file Par02FastSimModelTracker.cc
/// \brief Implementation of the Par02FastSimModelTracker class

#include "Par02FastSimModelTracker.hh"
#include "Par02EventInformation.hh"
#include "Par02PrimaryParticleInformation.hh"
#include "Par02Smearer.hh"
#include "Par02Output.hh"

#include "G4Track.hh"
#include "G4Event.hh"
#include "G4RunManager.hh"
#include "g4root.hh"

#include "Randomize.hh"

#include "G4Electron.hh"
#include "G4Positron.hh"
#include "G4Gamma.hh"

#include "G4PathFinder.hh"
#include "G4FieldTrack.hh"
#include "G4FieldTrackUpdator.hh"
#include "G4SystemOfUnits.hh"

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Par02FastSimModelTracker::Par02FastSimModelTracker( G4String aModelName, 
  G4Region* aEnvelope, Par02DetectorParametrisation::Parametrisation aType ) :
  G4VFastSimulationModel( aModelName, aEnvelope ), fCalculateParametrisation(),
  fParametrisation( aType ) {}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

Par02FastSimModelTracker::Par02FastSimModelTracker( G4String aModelName, 
                                                    G4Region* aEnvelope ) :
  G4VFastSimulationModel( aModelName, aEnvelope ), fCalculateParametrisation(),
  fParametrisation( Par02DetectorParametrisation::eCMS ) {}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

Par02FastSimModelTracker::Par02FastSimModelTracker( G4String aModelName ) :
  G4VFastSimulationModel( aModelName ), fCalculateParametrisation(),
  fParametrisation( Par02DetectorParametrisation::eCMS ) {}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

Par02FastSimModelTracker::~Par02FastSimModelTracker() {}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4bool Par02FastSimModelTracker::IsApplicable( const G4ParticleDefinition& 
                                                                   aParticleType ) {
  return aParticleType.GetPDGCharge() != 0;  // Applicable for all charged particles
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4bool Par02FastSimModelTracker::ModelTrigger( const G4FastTrack& /*aFastTrack*/ ) {
  return true;  // No kinematical restrictions to apply the parametrisation
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

void Par02FastSimModelTracker::DoIt( const G4FastTrack& aFastTrack,
                                     G4FastStep& aFastStep ) {

  G4cout << " ________Tracker model triggered _________" << G4endl;

  // Calculate the final position (at the outer boundary of the tracking detector)
  // of the particle with the momentum at the entrance of the tracking detector.

  G4Track track = * aFastTrack.GetPrimaryTrack();
  G4FieldTrack aFieldTrack( '0' );
  G4FieldTrackUpdator::Update( &aFieldTrack, &track );

  G4double retSafety = -1.0;
  ELimited retStepLimited;
  G4FieldTrack endTrack( 'a' );
  G4double currentMinimumStep = 10.0*m;  // Temporary: change that to sth connected
                                         // to particle momentum.
  G4PathFinder* fPathFinder = G4PathFinder::GetInstance();
  /*G4double lengthAlongCurve = */ 
  fPathFinder->ComputeStep( aFieldTrack,
                            currentMinimumStep,
                            0,
                            aFastTrack.GetPrimaryTrack()->GetCurrentStepNumber(),
                            retSafety,
                            retStepLimited,
                            endTrack,
                            aFastTrack.GetPrimaryTrack()->GetVolume() );

  // Place the particle at the tracking detector exit 
  // (at the place it would reach without the change of its momentum).
  aFastStep.ProposePrimaryTrackFinalPosition( endTrack.GetPosition() );

  // Consider only primary tracks (do nothing else for secondary charged particles)
  G4ThreeVector Porg = aFastTrack.GetPrimaryTrack()->GetMomentum();
  if ( ! aFastTrack.GetPrimaryTrack()->GetParentID() ) {
    Par02EventInformation* info = (Par02EventInformation*) 
                            G4EventManager::GetEventManager()->GetUserInformation();
    if ( info->GetDoSmearing() ) {
      // Smearing according to the tracking detector resolution
      G4double res = fCalculateParametrisation->
        GetResolution( Par02DetectorParametrisation::eTRACKER, 
                       fParametrisation, Porg.mag() );
      G4double eff = fCalculateParametrisation->
        GetEfficiency( Par02DetectorParametrisation::eTRACKER,
                       fParametrisation, Porg.mag() );
      G4ThreeVector Psm;
      Psm = Par02Smearer::Instance()->
                                 SmearMomentum( aFastTrack.GetPrimaryTrack(), res );
      Par02Output::Instance()->FillHistogram( 0, ((Psm.mag()/MeV) / (Porg.mag()/MeV)) );
      // Setting the values of Psm, res and eff
      ( (Par02PrimaryParticleInformation*) ( const_cast< G4PrimaryParticle* >
          ( aFastTrack.GetPrimaryTrack()->GetDynamicParticle()->GetPrimaryParticle() )->
            GetUserInformation() ) )->SetTrackerMomentum( Psm );
      ( (Par02PrimaryParticleInformation*) ( const_cast< G4PrimaryParticle* >
          ( aFastTrack.GetPrimaryTrack()->GetDynamicParticle()->GetPrimaryParticle() )->
            GetUserInformation() ) )->SetTrackerResolution( res );
      ( (Par02PrimaryParticleInformation*) ( const_cast< G4PrimaryParticle* >
          ( aFastTrack.GetPrimaryTrack()->GetDynamicParticle()->GetPrimaryParticle() )->
            GetUserInformation() ) )->SetTrackerEfficiency( eff );
    } else {
      // No smearing: simply setting the value of Porg
      ( (Par02PrimaryParticleInformation*) ( const_cast< G4PrimaryParticle* >
          ( aFastTrack.GetPrimaryTrack()->GetDynamicParticle()->GetPrimaryParticle() )->
            GetUserInformation() ) )->SetTrackerMomentum( Porg );
    }
  }
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......